What’s Vulnerable › Vulnerabilities

CVE-2025-61598: Discourse is missing Cache-Control response header on error responses

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-10-28 · updated 2026-10-19
• Weakness: CWE-524

Description

Discourse is an open source discussion platform. Version before 3.6.2 and 3.6.0.beta2, default Cache-Control response header with value no-store, no-cache was missing from error responses. This may caused unintended caching of those responses by proxies potentially leading to cache poisoning attacks. This vulnerability is fixed in 3.6.2 and 3.6.0.beta2.

Affected products

• discourse: before 3.5.2; before 3.6.0; 3.6.0-beta1 — fixed in 3.5.2, 3.6.0

How to fix

Upgrade to a fixed version: discourse 3.5.2, 3.6.0. Check the vendor advisory for mitigations.

References

• https://github.com/discourse/discourse/commit/3ea1b663c82c067e5ca778db846bad1e082ba6cd
• https://github.com/discourse/discourse/commit/fd567af7bf5a15c70772021acbdf5d38487a31bc
• https://github.com/discourse/discourse/security/advisories/GHSA-jp9x-wwv6-cv3j

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